Plan B Side Effects: What to Expect

An emergency contraceptive pill such as Plan B can be used to prevent pregnancy after unprotected sex or if your regular birth control failed (for example, if the condom broke or you forgot to take your regular birth control pill). Please continue reading to learn about the side effects of Plan B, also called the “morning after” pill.

How does emergency contraception prevent pregnancy?

Plan B One-Step is one of the most popular emergency contraceptives that is available without a prescription. It contains levonorgestrel 1.5 mg, which is a synthetic form of the sex hormone progesterone. There are different forms of emergency contraceptives. Plan B contains levonorgestrel as the active drug and prevents pregnancy by temporarily delaying the release of an egg from the ovary, thus, preventing ovulation. Another way that levonorgestrel works is to make it more difficult for sperm to enter the uterus.

Plan B One-Step is a single-dose treatment. You should take the tablet as soon as possible and within 72 hours of unprotected intercourse or birth control failure. Similar to Plan B One-Step, Next Choice One Dose also contains one single pill with 1.5 mg of levonorgestrel as the active drug.

Don’t get confused with the previous version, called Next Choice. Unlike Plan B One-Step and Next Choice One Dose, Next Choice is a two-tablet treatment containing two 0.75 mg levonorgestrel pills. With Next Choice, you take the first tablet as soon as possible, within 72 hours of unprotected sex. The second tablet should be taken 12 hours later. Another major difference is that Next Choice requires a prescription for women younger than 17 years of age, though it is available over the counter for women 17 years and older.

Plan B One-Step and Next Choice One Dose are available over the counter (OTC) to people of all ages. You can take emergency contraceptive pills anytime during your menstrual cycle. As mentioned, for levonorgestrel-containing morning-after pills, you have up to 72 hours after unprotected sex to take the medicine. However, the sooner you take it, the better.

Another important fact to keep in mind is that levonorgestrel emergency contraceptives may not be as effective for women weighing more than 165 pounds (75 kilograms).

It is worth noting that Plan B and other emergency contraceptives do not protect against HIV and other sexually transmitted infections.

What are the other options for emergency contraception besides Plan B?

Besides Plan B, there are other options for “morning after” pills that contain levonorgestrel, such as AfterPill, My Way, Aftera, Preventeza, Option 2, Take Action, My Choice, and EContra.

The other option for emergency contraception is a medication called ulipristal acetate. There is only one brand available called Ella. Ella requires a prescription from your healthcare provider. Remember that telemedicine companies such as Nurx also offer fast and convenient virtual consultation with next day delivery options. With Ella, you have up to 120 hours (5 days) after unprotected sex to prevent pregnancy, though it is best to take the pill as soon as possible.

Taking a large dose of your regular birth control pill may also work. However, only certain brands of birth control can be used for this purpose. You should always check with your healthcare provider to make sure this is a safe and effective option for you.

Besides taking emergency contraception pills, another method of preventing pregnancy is to have an intrauterine device (IUD) such as ParaGard inserted by a healthcare professional within 5 days of unprotected sex. You can have the IUD removed after your next period or leave it in place for continued protection against pregnancy.

It’s worth noting that unlike an abortion pill such as mifepristone (Mifeprex) or RU-486, an emergency contraceptive like Plan B cannot terminate an established pregnancy.

How long does it take for a Plan B pill to kick in?

For maximum effectiveness, you should take the “morning after” pill Plan B within 3 days (72 hours) of unprotected sex. You can take it at any time during your menstrual cycle. The earlier you take Plan B, the more effective it is likely to be. After you take Plan B, the medication reaches peak concentration in 1.7 hours and prevents ovulation for the next few days.

What are the side effects of the “morning after” pill?

Plan B contains 1.5 mg of levonorgestrel, making it three times more potent than a regular birth control pill. Therefore, this concentrated dose can cause some short-term side effects. Potential side effects of emergency contraception such as Plan B include:

Lower abdominal pain or cramps
Changes in the menstrual cycle, such as lighter or heavier menstrual bleeding or next period being late
Spotting or bleeding between periods
Fatigue
Nausea
Vomiting
Diarrhea
Bloating
Headache
Dizziness
Breast tenderness

You can take an over-the-counter pain reliever and anti-nausea medicine to reduce discomfort.

Does cramping after Plan B mean it's working?

Cramping after Plan B does not necessarily mean it is working. Taking Plan B causes hormone fluctuations which can cause side effects. Lower abdominal cramps are one of the side effects of Plan B. However, you cannot rely on these side effects to tell if the emergency contraception worked. The only way to know for sure if Plan B worked is to wait for your period. If your period is more than a week late, you should take a pregnancy test.

How long after taking Plan B do you feel side effects?

Everybody’s reaction to Plan B can be different. However, the usual timeline when side effects resolve after Plan is as follows:

Day 1: Mild side effects can develop within two hours of taking the pill. These may include nausea, vomiting, headaches, and breast tenderness. If you vomit within two hours of taking Plan B, talk to your doctor about the need to take a second dose.

Days 2-3: Side effects such as fatigue, nausea, pelvic pain, headache, and breast tenderness may continue.

Days 4-5: Side effects start decreasing, but there can be some lingering headaches and breast tenderness.

Day 6 onwards: Menstrual changes such as irregular bleeding or spotting can continue for up to 4 weeks after taking a “morning after” pill such as Plan B.

How effective is Plan B?

If you take Plan B within 72 hours of unprotected sex, it can lower your risk of an unwanted pregnancy by 75-89%. The sooner you take it, the more effective the “morning after” pill is likely to be.

Notably, levonorgestrel-containing emergency contraception such as Plan B tends to be less effective in women who weigh more than 165 pounds. Similarly, Ella doesn’t work as well for women weighing more than 195 pounds. If this is the case, talk to your healthcare professional about another method of emergency contraception, such as IUDs. Weight does not affect the effectiveness of IUDs as long as it is placed by a medical professional within 120 hours (5 days) of unprotected sex.

Also, keep in mind that certain medications and herbal supplements, such as St. John’s Wort, can make emergency contraceptives less effective. You should talk to your doctor or pharmacist as soon as possible to make sure there are no drug interactions between the emergency contraception and your current medications.

Anyone who has had an allergic reaction to levonorgestrel in the past should not take Plan B.

Do I need to see a doctor after taking Plan B?

Plan B is an over-the-counter emergency contraceptive. You do not usually need to see a doctor after taking it. However, you should call your doctor without delay if you have severe lower abdominal pain - this can happen up to 5 weeks after you take Plan B.

Is it safe to take Plan B multiple times? Can I use Plan B for regular birth control?

It is safe to take a “morning after” pill such as Plan B as often as required. However, emergency contraceptives like Plan B are not for routine use. Plan B should not be used as a substitute for regular birth control. “Morning after” pills are not as effective or reliable as a regular birth control method. If you need to use Plan B more than a couple of times a month, talk to your healthcare provider about a regular birth control method that fits your preference and lifestyle.

Also, for morning-after pills like Plan B One-Step that contain only 1 pill, you do not need to take additional doses. This does not make it more effective.

You can take levonorgestrel pills like Plan B several times as needed during the menstrual cycle. On the contrary, Ella (ulipristal acetate) must only be taken one time during the menstrual cycle.

References: